Automatic gear shift for automobiles



AUTOMATIC GEAR SHIFT FOR AUTOMOBILES Filed May 22, 1933 5 Sheets-Sheet l T 0 Inta/f e Man/fold 75Dr/ve Shaft or .Dr/vm A el f Z'mventor A t b U 0m fiAI ILAND H HATT.

Gttomeg April 13, 1937. H. H. PLATT 2,076,791

I AUTOMATIC GEAR SHIFT FOR AUTOMOBILES Filed May 22, 1955 5 Sheets-Sheet 2 4 31 3nventor AQVILAN HPLA TT April 13, 1937. H. H. PLATT AUTOMATIC GEAR SHIFT FOR AUTOMOBILES I Filed May 22, 1953 5 Sh'eetsSheet 5 April 13, 1937. H. H. PLATT AUTOMATIC GEAR SHIFT FOR AUTOMOBILES Filed May 22, 1933 5 Sheets-Sheet 4 inventor HAVILAND H PLATT April 13, 1937. H. H. PLATT 2,976,791

I AUTOMATIC GEAR SHIFT FOR AUTOMOBILES- Filed May 22, 1933 5 Sheets-Sheet 5 Bnventor HAVILAND H PLATT (Ittomeg LU u..u 252 ILLLJ 2177 250 1 7 l-LLJ Patented Apr. 13, 1937 UNITED STATES PATENT OFFICE AUTOMATIC GEAR SHIFT FOR AUTO MOBILES Application May22, 1933, Serial No. 672,367

17 Claims.

My invention relates to a new and useful improvement in power transmission for automobiles and other vehicles, and it relates more particularly to automatic means for varying the mechanical ratio between the shaft of the prime mover, such as the internal combustion engine, and the rear. or driving axle of the vehicle, as required by the various conditions of operation.

My invention relates more particularly to an automatic gear-shifting device, which may either include speed change gears, or which may be made auxiliary to speed change devices now in use on automobiles.

Thus, it is an object of my invention to provide means whereby the various changes in mechanical ratio between the engine shaft and the driven wheels of an automobile, (as for instance, the gear shifting of an automobile) may.be made automatic and yet responsive to the requirements of each of the many conditions of operation encountered at any time.

With the above and other objects in view,

- which will appear more fully from the following detailed description, my invention consists of 5 means which may be associated with any of the forms of standard or conventional speed change devices now generally in use in automobiles, to render said speed change device automatic and responsive to the condition of the engine and the relative speed between engine and drive shaft.

My invention further consists of a combination of speed change means, and control means therefor;the latter being in turn responsive to engine conditions and relative speed conditions of engine shaft and automobile drive shaft.

My invention further consists of power actuated means for shifting the gears into mesh in any one of several positions, and power actuated means for shifting the gears into neutral from any position, that is, disengaging any one of the several different gears of a system of speedchange gears. In the present embodiment of my invention, these power actuating means are pneumatic means, which derive their power a from compressed air supplied from any suitable air compressor, and a suitable reservoir, in which a generally constant supply of air at generally constant pressure is maintained by any suitable governor or pressure relief device, or both;the compressor being preferably driven from the engine of the automobile.

My invention further consists of selector 5;. mechanism, controlling each of said power actuating means and being in turn controlled by, or responsive to the rotational speed of the shaft of the engine; the rotational speed of the drive shaft (or driven wheels), the vacuum condition in the intake or inlet manifold of the 5 engine, and the position of the speed change gears themselves.

The present invention further consists of a series of interrelated valves within said selector mechanism and centrifugal means for position- 10 ing two of said valves, pneumatic means for positioning another of said valves, and mechanical means connected with the gear shift bars for moving the other two of said valves;-all

interrelated by passages and'movable and sta- 15 tice to give satisfactory and reliable results, al-

though it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized 30 and that my invention is not limited to the precise arrangement and organization of the instrumentalities as herein shown and described.

Referring to the drawings in which like reference characters indicate like parts: 5

Figure 1 represents a generally diagrammatic view showing the relationship between the several component parts of my present invention, that is, the relationship between the powered gear actuating means, that is, the air cylinders, 40 the gear shifting slides, the neutral mechanism, the selector mechanism or selector box, the air compressor, and the manually operated control valves which are preferably placed on the dash-board or some other convenient point, for setting the automatic gear shift for operating the car in reverse and for also totally disconnecting the automatic gear shift when manual operation of the gear shift is desired for any reason.

Figure 2 represents a plan view of the air powered gear shift actuating mechanism, with the central portion thereof partly broken away and sectioned, generally on line 22 of Figure 3, thereby to expose to view the neutral cylinder and the neutral slide. In this Figure 2, the two concentric transmission shafts are omitted.

Figure 3 represents a section on line 3--3 of Figure 2, illustrating the transmission shafts and 5 the shifting slides, and the racks and pinions through which the power is transmitted to the same.

Figure 4 represents an end elevational view of the air powered gear shifting mechanism,

7 10 partly sectioned on line 44 of Figure 2.

Figure 5 represents a section generally on line 5-5 of Figure 3, illustrating the relationship between the transmission shafts and the racks and pinions oy which the motion is trans- 15 mitted therefrom to the shifting slides.

Figure 8 represents a top plan view of the selector mechanism or selector box with-the 25 upper cover plate removed therefrom, so as to expose to view the air passageways.

Figure 9 represents a section generally on line 9-9 of Figure 8.

Figure 10 represents a schematic sectional 30 view on line ||0 of Figure 1, on a much enlarged scale.

In carrying out my invention, any suitable or conventional type of speed-change device or gear box may be employed, generally having three forward positions and having one reverse position.

For purposes of illustration, 9. standard threespeed gear box is assumed and represented generally by the letter G, in which the gears have 40 the standard gear shift positions for all three forward speeds as well as for reverse. In the diagrammatic view of Figure 1, the engine is represented generally by the letter "13, and the clutch housing by the letter C.

45 The -2nd and high" slide l0, and the "1st and reverse slide ll, both represented generally diagrammatically in Figure 1, are of any conventional standard construction and adapted to be engaged alternately and selectively by the lower end of the manual gear shift rod designated generally by a circle identified by the numeral l2 in Figure 1. The conventional gear shift slides l0 and II are provided with pins 3 and,

M, respectively.

55 Within the upper cover plate I 5 of the gear box housing G, a pair of levers l8 and I! are provided, preferably superimposed upon each other, and carried by a pair of concentric pivots l8 and I9, respectively, which extend through the cover 60 plate and are journalled in the cover plate. The free ends of the levers l6 and H, are slotted or bifurcated longitudinally and engage the pins I3 and M respectively, so that a deflection of the lever shifts the slides Ill and II, respectively.

65 To the outer ends of the concentric pivots I8 and I3, a pair of similar levers 20 and 2| are secured. The free ends of the levers 2|! and 2| are in turn pivotally connected, by means of pivots 22 and 23, to the shift operating cross- 70 slides in the air-powered gear actuating mechnism shown in detail in Figures 2, 3, 4, 5 and 7, and to the gear-position valves in the selector mechanism shown in detail in Figures 8 and 9.

The gear shifting mechanism includes two (or 5 more, depending on the number of shift slides in the gear box and the number of gear positions) concentric transmission shafts 24 .and 25 respectively, the inner shaft being suitably Journalled in any suitable bearing members 26 and 21, and the outer tubular shaft 25 being'journalled in the bearings 23;said bearings 26, 21 and 29 being carried by the housing 28. The gear shifting mechanism further includes two (or more) opposed pairs of air-cylinders (and corresponding pistons therein) on opposite sides of the transmission shafts;said air cylinders being designated generally by the numerals 30, 3|, 32 and 33, and being, respectively, the 1st gear cylinder; the reverse-gear cylinder; the "2ndgear cylinder; and "high-gear cylinder.

At one end of the actuating mechanism is the neutral cylinder 34, generally at a right angle to the cylinders 3|], 3|, 32 and 33, as seen particularly in Figures 2, 3 and 7.

To each of the transmission shafts 24 and 25, generally similar crank levers 35 and 36 are secured, by suitable keys 31 and 38, respectively. The crank levers 35 and 36 may have generally arcuate terminal surfaces 39 or any other surface of no greater radial dimension. Each of the crank levers has a pair of opposed and generally rounded contact projections or knobs 40 and 4|, respectively;-said contact projections or knobs being in suitable spaced relation to each other, and to the ends of the opposed piston rods 44 of the actuating pistons 42.

Each of the cylinders 30, 3| Hand 33, has disposed within it a piston 42, of any suitable construction, and having any suitable packing means, such as the piston rings 43 or the like, for establishing a sliding seal between the piston and the cylinder-wall against the air pressure. Each piston 42 carries a piston rod or plunger 44, which extends through a suitableopening 45 in the inner cylinder closure member or cap member 46 and which is slidably mounted therein. A helical compression spring -41 is interposed between each piston 42 and inner cylinder-head or cap or closure member 45 for returning the piston 42 and piston rod or plunger 44 to its outermost or initial position when the air is reliev'ed;the piston and plunger moving through its operative stroke in the direction of the arrow 48, under the action of compressed air which is.

admitted into the space 49 between the piston 42 and outer cylinder head 5| through the port 50 by the slide valve 52. f

The maximum radial dimension of each of the crank levers 35 and 36,'and the distance between the two contact points 40 and 4| of said levers is so proportioned with respect to each other, that while the contact projections 40 and 4| are in operative alignment with the ends of the plungers 44, when the levers are in their central or "neutra position (shown particularly in Figure 4), the crank-lever clears the ends of the plungers 44 on either side when defiected by the action of the plunger from the other side. Thus, there is a suitable amount of radial clearance 53 between the radially outermost parts, of the crank levers 35 and 36 and the ends 01' the corresponding pair of opposed plungers 44 when the respective plungers 44 andpistons 42 are in their retracted positions shown in Figure 4. By re'a- I corresponding plunger upon it, without interfering with the opposite plunger which is then inoperative;the levers 35 and 36 clearing the end of the retracted or inoperative plunger 44.

The opposite ends of the transmission shafts or pivots 24 and 25 carry fragmentarypinions or toothed segments and 56, respectively, which may be either formed integrally with said shafts or pivots, or which may be secured thereto. Beneath and in operative alignment with the pinions 55 and 56, and extending transversely of and generally at a right angle to the axis of the pivots or'transmission shafts 24 and 25, toothed rack members 51 and 58 are provided, each slidably mounted within the housing 28. The toothed rack members 51 and 58 are provided with teeth 59 and 60 respectively, which are in mesh with the toothed segments or fragmentary pinions 55 and 56, respectively, thereby transmitting the motions of the shafts or pivots 24 and 25 to the rack members 51 and 58; thereby also translating the arcuate or rotary motions of the former into corresponding rectilinear motions of the latter.

Generally adjacent to each of the toothed rack members 51 and 58, secondary slides BI and 62 are provided, extending generally parallel to the rack slide members 51 and 58, and being so slidably mounted in the housing 28.

The secondary slides 6| and 62 borrow rectilinear motion from the toothed rack slide members 51 and 58, respectively, by means of pins or projections 63 and 64, rigidly carried by the toothed rack slide members 51 and 58, respectively, which extend into and fit loosely within corresponding elongated slots and 66 in the secondary slides 6| and 62, respectively. The slots 65 and 66 are somewhat shorter than the length of travel of the toothed rack slides 51 and 58, and said slots 65 and 66 are positioned centrally with respect to the pins 63 and 64, when the pins 63 and 64 and the slides 6| and 62 are in their neutral positions. By this means, the toothed rack slides 51 and 58, and the pins 63 and 64 carried thereby, may return to their central or neu tral positions, after each displacement (in either direction) without drawing back with them the secondary slides 6| and 62, since the length of the slots 65 and 66 are sufficient to clear the pins 63 and 64, respectively, upon the return of the rack slides 51 and 58 to the neutral positions. Hence, the transmission shaft 24 or 25 (as the case may be) with its corresponding rocker lever 35 or 36, respectively, and the corresponding toothed segment or fragmentary pinion 55 or 56 (as the case may be) may return to their central or neutral position as soon as the air pressure in the particular actuating cylinder is released by the selector valves;the shafts 24 and 25 being brought to their neutral position by the action of the'clutch spring of the automobile upon the similar cams 61 and 68 carried by said shafts and acted upon by a follower connected to the clutch pedal of the automobile (as will be described more in detail hereinafter) The general contour of the cams 61 and 68, carried by the transmission shafts 24 and 25, respectively, is shown particularly in the fragmentary sectional view in Figure 6. Each of the cams 61 and 68 (shown in the neutral position in Figure 6) is generally symmetrical with respect to a plane passing through the axis of the shafts 24 and 25 and passing through the axis or line of travel of the follower plunger 69. The follower plunger 69 is slidably mounted in a suitable opening 10 in the housing 28, and carries at its inner end a follower roll 1| rotatably mounted upon the pivot pin 12 in the slot 13 in the end of the plunger 69. Any suitable means, such as the screw 14, having suitable bare inner end 15 running in a longitudinal slot 16, may be provided for preventing any rotation of the plunger 69. A tubular plug 11 is screw-threaded into the cylindrical bore 10, and the outer endof the plunger 69 is slidably mounted within the bore 18 of said plug 11. A helical compression spring 19 is interposed between the inner end of the stationary plug 11 and the annular shoulder 86' of the plunger 69. The' spring 19 constantly urges the plunger 69 and the follower roller 1| towards the cams 61 and 68. Any suitable connecting means or connecting rod 8| may be provided intermediate the plunger 69 and the clutch lever of the automobile so that an outward movement of the plunger 69 in the direction of the arrow 82, caused by the rotational movement of either one of the two cams 61 and 68, in either of their two rotational directions, will cause the clutch to be dis engaged, or the engine to be dc-clutched from, the gear-box of the automobile.

' The plunger 69 is also connected, through any suitable connecting means such as the rod 8|, to the gas throttle of the engine with any suitable over-running motion or connection, and in such a direction that the outward movement of the plunger 69 in the direction of the arrow 82 will close the throttle to idling" position, regardless of the position of the gas-pedal or the. gaslever;under the operators control. The cams 61 and 68 are preferably so shaped, that by the first slight angular or rotational movement of the shaft 24 or the shaft 25, the plunger 69 will be moved outwardly to a substantial extent, and so that during the balance of the angular rotational movement of the shaft 24 or the shaft 25, the outward movement of the plunger 69 will be less in proportion to the angular movement. This is indicated by the contour of the cams shown in Figure 6. During the initial outward movement of the plunger 69, in the direction of the arrow 82, the gas throttle is closed down to idling, while the de-clutching movement of the clutch lever is in its initial stage. The final or complete de-clutching movement of the clutch lever is then brought about by the continued movement of the plunger 69 over the more gradual rise in the cam 61 or 68. v

The spring 19, augmented by the pressure of the clutch spring, serves to exert a rotational force upon the cams 61 and 68 which tends to return said cams, and hence, tends to return the shafts 24 and 25 to their neutral position, as the air pressure is released from the particular actuating cylinder 38, 3|, 32 or 33, which caused the rotational movement of the'particular shaft 24 or 25, and the corresponding cam 61 or 68 (as the case may be).

To the lower longitudinal edge of the toothed .rack slide 58, a latch type cam follower 84 is pivotally secured on the pivot 85, which in turn, is carried by the pivot supporting members or lugs 86 which extend downwardly from the slide 58 and may be formed integrally therewith.

The pivoted end of the latch 84 is rounded on one side and is provided with a square heel 81 on the opposite side, so that the latch may be deflected in the direction of the arrow 88, from its normal position shown in Figure 3, and so that it will be fixed against deflection in the direction'of the arrow 89, from its normal position shown in Figure 3. Any suitable spring, such as the double-ended helical torsion spring 90, pivoted on the outer projecting ends of the pivot 85, may be provided for constantly urging the latch 84 into its normal position shown in Figure 3. The free ends 9I of the spring 90 bear against the surface of the slide, while the intermediate portion 92 of the spring bears against the latch 84.

Each of the secondary slides 6| and 62 is provided with similar latch-type cam followers 93 and 94, respectively, mounted upon pivots 95 and 96, respectively. The latches 93' and 94 are similar in shape, but are different-in dimensions from the latch 84. Thus, the latch 84 has greater radial length or depth, while the latches 93 and 94 have greater width. The latches 93 and 94 are similarly constructed, and are deflected in the direction of the arrow 88, and are anchored against deflection in the direction of the arrow 89. They are similarly urged into their normal position shown in Figure 3, by similar double-ended helical torsion springs, or anyother suitable means.

Within the housing 28, a sliding cam or slipper erally parallel to the axis of the shafts 24 and 25. The sliding cam or slipper cam 91 isconnected, through a suitable flat connecting rod 98, and the bolts 99, to a piston I00 mounted within the neutral cylinder 34.

The sliding cam or slipper cam 91 is provided with an inclined camming surface I02 at a lower level and a pair of similar inclined camming surfaces I03 and I04 at an upper level, symmetrical with respect to the longitudinal median line or axis I05.

The camming surface I02 which terminates in the dwell I06, is adapted to engage only the latch 84, while clearing the two shorter latches 93 and 94. The camming surfaces I03 and I04 are adapted to engage, alternately, either one or the other of the latches 93 or 94 ;whichever one of the two happens to be out of its neutral position.

The slipper cam 91 with its several camming surfaces, is moved through its operative stroke in the direction of the arrow I01, by a pair of suitable springs, such as the pair of helical tension springs I08 and I09, the movable ends of which 60 are fastened to corresponding pins II 0 and III,

which. extend freely through slots H2 and H3 in the lower wall II4 of the housing 28, and which are fixedly fastened into or anchored in suitable holes in the slipper cam 91. The stationary ends of the springs I08 and I 09 are fastened to any suitable stationary spring anchorages on the neutra cylinder.

The piston I00, and hence the slipper cam 91, are normally maintained in the position shown in Figure 2, by air pressure normally maintained within the "neutral cylinder. Only while shifting any of the gears into "neutraP, is the pressure p in the neutral cylinder released, and the slipper cam 91 caused to travel through its operative stroke in the direction of the arrow I01 under the influence of the helical tension springs I08 and I09.

In travelling through its operative stroke, in 0 the direction of the arrow -I01, the slipper cam 91 first engages the latch 34 by means of the camming surface I 02 and moves the latch 84 as well as the rack slide member 38 to'one side of its "neutral or central position (shown in Figure 2) 75 against the force of the clutch spring of the auto-' cam 91 is slidably mounted, in a direction genmobile and the force of the spring 19 (Figm'e 6) acting on the cam 68;until the latch 84 rides on the dwell I06. This deflection of the rack slide 58 causes a disengagement of the clutch of the automobile through the push rod or connecting rod or other connecting means 8| (Figure 6) and also causes the throttling down of the engine in timed relation to the de-clutching action. The action of the cam I02 upon the latch 84 is sufficiently in advance of the action of either cam I03 or I04 upon either latch 93 or 94 (depending on which of these two latches happens to be off its neutral or central position) so that the clutch of the automobile will have been disengaged before the particular "gear" is shifted into "neutral by the action'of either cam I03 or cam I04 upon either latch 93 or 94. Upon the completion of its full operative stroke in the direction of the arrow I01, the edge or end wall II6 of the slipper cam 91 contacts the end I I1 of the slide valve H8 and forces it in the direction of the arrow I01, thereby again to admit air into the neutral cylinder (in a manner which will be described more in detail hereinafter) thereby automatically and instantly returning the slipper cam 91 into its normal position shown in Figure 2, after each operative st10ke; the operative stroke being merely for clearing the gears, that is, disengaging the particular gear which happens to be engaged and instantly throttling down the engine and declutching the engine, preliminary to such gear disengagement. During the return stroke of the slipper cam 91, under the influence of compressed air (acting against the springs I08 and I 09), the latches 84, 93 and 94 are deflected about their respective pivots, so that the camming surfaces I02, I 03 and I04 can have no .effect upon said latch members nor upon the slides which carry said latch members, regardless of the position of said latches and slides. As explained hereinabove, the latches 84, 93 and 94 Y can be deflected in the direction of the arrow 88, but are firm in the direction, of the arrow 89 the deflection in the direction of the arrow 88 being against suitable spring tension created by the double helical torsion springs 92 or other suitable spring members or yieldable resistance means.

Each of the cylinders 30, 3|, 32, 33 and 34, being respectively, the 1st"; reverse; second"; high; and neutra cylinders, is controlled directly by corresponding slide valves I20, I2I, I22, I23, and H8, respectively.

Each of the slide valves I20, I2l, I22, I23 and H8, is of the snap type or trigger type, so that after the slide valve has been moved in either direction through part of its travel, it automatically moves through the balance of its travel in the same direction under the influence of a spring and with a more or less instantaneous action. Thus, with each of said slide valves, 9. pivotally mounted trip arm I 24 is associated; mounted upon a suitable pivot I25 on a bracket I23, and

having a rounded end I21 extending through a.

suitable slot I28 in the wall of the stationary housing of the slide valve, and extending into a suitable notch I29 in the slide valve. The trip member I24 contains a spring arm I30, at 90, more or less, to the main arm thereof,.which is engaged by a spring yoke I3I, which in turn, is acted upon by the pair of helical tension springs I32 and I33, the opposed ends of which are anchored to suitable spring anchorages I34;- the tension or force of said springs being adjustable through the nuts or other suitable screwrection, and a stationary inlet port I31, through which air may be admitted intothe cylinder to actuating the gear-shifting piston 42.

The slide-valve members I20, I2I, I22, and I23 are each slidably mounted within corresponding cylindrical openings in their respective stationary housings, and a pin orother suitabledevice L38 is carried by each of said slide-valves; with the opposed ends thereof projecting beyond the body of the slide-valve member and extending into corresponding slots I39 and I46 in the housing:-' with the inner end I4I of the pin extending into the corresponding air cylinder, and into the path of the gear-shifting piston 42.

In the normal inoperative condition, the gearshiiting pistons 42 are in the retracted position indicated in Figure 4, and the corresponding slide-valves are in the position also shown in Figure 4. In this position. the inlet ports I31 are closed off by the slide-valve. The operation, controlled by the selector mechanism hereinafter described, is first to admit air through the port I36, into the space I42, between the end of the slide valve and the stationary closure plug I43, thereby causing the slide-valve to be displaced in the direction of the arrow I43. This displacement continues under the influence of the compressed air admitted through the statlonary port I36, until the. spring yoke passes the center I of the support of the trigger arm I24. Thereafter, the force of the compressed air admitted through the port I36 .is augmented by the force of the springs I32 and I33. By reason of the force of the springs, the balance of the travel of the slidevalve in the direction of the arrow I43, is effected in an instantaneous manner, causing the movable port I44 of the slide-valve member to come into registration with the stationary port I31, and the stationary port 50, thereby establishing communication between the air reservoir and the space within the particular cylinder behind the gear-shift piston 42. Under the influence of the compressed air which is thus admitted through the port I31, the particular gear-shifting piston 42 is caused to travel the full length of its stroke against the force of the spring 41, thereby effecting a shifting of the particular gear in a manner hereinabove described. As the gear-shifting piston 42 travels the last portion of its operative stroke, it encounters the lower end I M of the pin I38 of its slide-valve, and carries said pin and slide-valve with it until the spring yoke I3l passes the dead-center of the trigger arm I24 and until the latter thereby moves the slide-valve through the-balance of its travel in the same direction. This returns the slide-valve into its initial position shown in Figure 4, in which position the stationary port 50 is opened to the atmosphere, thereby permitting the spring to a stationary relief port I46, in advance of the ,tion with the neutral cylinder.

port 50, in' the same cylinder, through which ports I45 and I46 additional relief is given for the exhaust of the air through the slot I28. The outer ends of the cylindrical valve housings, housing the slide valves I20 and I2I of the 1st" and reverse slide-valve members I 20 and I2I, are closed off by slow-relief plugs I41, having relatively small relief apertures I48. By means of this slow-relief device; the return movement of the gear-shifting piston 42 in the 1st and reverse cylinders, is checked or slowed down 1 through the last portion of its return travel, so

as to moderate the re-engagement of the clutch of the automobile and the opening of the gas throttle, thereby to obtain a. smoother start, or a more gradual acceleration of the automobile in 1st and in reverse. Thus, through the first portion of the return movement of the gear-shifting piston (under the influence of the return spring 41), the air is exhausted rapidly through the ports I45 and I46 and the slot I20. This rapid exhaust causes the rapid return movement of the gear-shifting piston until the gear-shifting piston closes oil the port I46, after which the return movement of the gear-shifting piston-is checked and slowed down by the relatively smaller diameter of the exhaust opening I48 in the plug I41. The size of the opening I 48 is predetermined according to the clutch action desired in 1st and reverse. If desired also, the opening I40 may be controlled by the longitudinal inclination of the automobile. Thus, if desired, the plug I41 in the opening I48 therein,

' may be augmented by a valve in connection with said opening I48, the position of which valve would be controlled by a pendulum-like weight which would be responsive to forward and rearward inclinations of the automobile, so that the re-engagement of the cliltch will be slower or cylinder, and the outer end of which is in reg-' istration with'the stationary inlet port I5I in the valvehous'ing in one extreme position of the slide valve H8, and which is in registration with the stationary relief port I52 in the valve housing, in the other extreme position of the slide valve H8. The slide valve- I I8 of the neutral cylinder is controlled by a trigger arm I24, spring yoke I3I, and springs I32 and I33, similar to the trigger arms which are associated with each of the slide valves I20 and I23 inclusive, of the gear-shifting cylinders 30, 3I, 32 and 33.

Thus, the normal or inoperative position of the neutral cylinder, and the normal position of the slide valve H8 is that shown in Figure 2, wherein the air inlet port I5I is in communica- To the end I54 of the valve chamber containing the slide valve I I8, a certain air line I53 is connected from the selector mechanism, through which an impulse of compressed air may be supplied momentarily, against the outer end of the slide-valve.

H0, thereby moving said slide valve in the direction of the arrow I55, towards its relief position;said slide valve being carried through the latter portion of its travel by the force of the springs I32 and I33, acting through the trigger arm I24. In the relief position, the air is exhausted and the slipper cam 91 is returned under the influence of the springs I08 and I09.

The automatic control The gear shifting and clearing cylinders,

. to wit, the 1st, reverse, "second and high cylinders, and the neutral cylinder, forming a part of my present invention, are each connected with two diflerent air lines or air conduits.

One air conduit or air line or connection interconnects the main inlet port or cylinder-actuating port with a source of compressed air, such as an air compressor I60 and air reservoir I6I, through which compressed air is supplied to the respective gear-shifting pistons, as well as to the neutral piston, that is, the piston which clears the gears, for the purpose of causing said pistons to move through one of their two strokes. By this compressed air, the gear-shifting pistons are moved through their respective operative, or gear-shifting strokes, while through this compressed air the neutral piston is moved through its inoperative stroke and maintained in its normal position against the force of the springs I08 and I09, which in turn tend to move said neutral piston and the associated slipper-cam 91 through their operative stroke.

Another set of air conduits or air lines interconnects another port of each of said cylinders (1st, reverse, 2nd, "high and neutral), and the control housing or selector" housing I10. This second set of air conduits or air lines is for the purpose of controlling the snap valves or slide valves of the respective cylinders and is connected to the ports in the valve housings of the respective cylinders, through which said snap valves or slide valves are actuated in one direction.

In Figures 8 and 9 I have illustrated the selector means, to which the air-inlet ports governing the snap valve action of the various cylinders are connected, and whereby the cylinders are actuated, responsive to the various conditions of en-' gine speed, automobile speed, and intake-manifold vacuum.

The selector means, designated generally by the numeral I10, includes a main valve housing "I, having a series of valve chambers, which may be generally cylindrical openings, as indicated in Figures 8 and 9, and within'which suitable valve members I12, I13, I14, I15, and I16 are slidably mounted. The valve chambers are interconnected by passageways which will be described more in detail hereinafter. In the particular embodiment of my invention herein shown, the connecting air passageways within the valve housing I1 I, are formed by grooves provided in the outer surface I11 of the valve housing I1 I, and holes extending down from said grooves to the valve chambers. A cover member or cover plate I18, is then fastened down upon the grooved surface I" of the valve housing IN, to form the outer wall of the grooves in the surface I11, which thereby form the air passageways. The cover plate I18 may be fastened by a suitable series of fastening means, such as the bolts I19 or the like. The connecting air lines are also connected to the cover plate I18, which is provided with suitable internally threaded openings or other suitable pipe-receiving sockets or means.

To the valve housing "I, two generally similar is secured to the housing by a screw-threaded.

coupling collar or sleeve engaging the screw threads I86.

The coupling member I83 carries the opposed pivot members I81. To the valve element or member I12 (and the valveelement I13 is similar in this respect) the collar I88 is secured, having a pair of similar pivot members I89. The outer end of the valve element or member I12 is slidably coupled to the coupling member I83, by means of a pin I90, which extends through the coupling member I83 and is secured therein, and which extends loosely through an elongated slot I9I in the free end of the valve member I12. The free slotted end of the valve member I12 fits loosely within a corresponding axial bore I92 in the coupling member I83. A helical compression spring I93 is operatively interposed between the axially immovable coupling member I83 and the axially movable collar I88 (which is aflixed to the valve element I12). A pair of similar weights I94 are pivotally carried by pairs of links I95 and I96, which in turn are pivotally secured to the pivot members I81 and I89, respectively. Thus, the spring I93 tends to maintain the valve member I12 in its extreme position in the direction of the arrow I91, while the centrifugal force upon the weights I94, due to the rotation of the governor, tends to move the valve element I12 in the direction of the arrow I98. The flexible shaft (not shown in Figure 8) from the=governor housing I80, is connected to the drive shaft or propeller shaft of the automobile, in any suitable mechanical ratio, to give the necessary centrifugal force required to move the valve element. In the present embodiment of my invention the governor controlled valve I12 is intended to turn at twice the speed of the propeller shaft or drive shaft of the automobile.

The governor I8I, controlling-the valve element I13, being similar to the governor I of the valve element I12, is connected, through a similar flexible shaft, to the crank-shaft of the The coupling member engine, and in the particular embodiment of my invention, is intended to turnat engine speed.

The valve element I14 is in turn connected to a piston 200, disposed in a suitable cylinder 20I, which terminates in a spring housing 202, and which is connected through a suitable opening 203 in a corresponding conduit or pipe line, to the intake manifold of the engine. A helical compression spring 204 is operatively interposed between the piston 200 and the terminal wall of position of balance between the force of the spring 204 and the force of the vacuum in the intake manifold upon the piston 200.

The valve elements I15 and I16 are in turn connected to the gear-shifting slides or secondary slides 62 and M respectively, and have, principally, two opposed operative positions in the two opposite limits of their travel and move in unison with the respective gear-shift slides I0 and II. (See Figure 1.)

Upon the dashboard or instrument panel 205,

or at any other suitable place within the drivers reach, a cut-out valve 206 and a reverse valve 201 are provided, which in Figure 1 are illustrated merely diagrammatically. Thus, the stationary valve housings of these valves are identified by the numerals 208 and 209, respectively, while the movable valve elements are identified by the numerals 2I0 and 2, respectively.

Each movable valve element 2| 0 and 2 is provided with any suitable manually operable handle or knob 2I2 and 2I3 respectively, by means of which each of said valves may be placed in either one of two operative positions, which may be defined by suitable stops or other means for limiting the movement of said valve element (such means not being shown in the drawings).

The valve housing 208 is provided with an inlet port 2 I 4, which is connected with the source of compressed air, such as the reservoir I6I or compressor I60 by means of a suitable conduit or piping 2I5. The valve housing 208 is also provided with another port 2 I6, which is adapted to be connected through a movable port or passageway 2", with the inlet port 2I4, while the automatic gear shifting mechanism is in operation. To the port 2I6 of the housing 208, the air supply lines 2I8 and 2I9 are connected, through which compressed air is supplied both for the operation of the gear shifting and gear 'clearing or neutral" pistons, as well asfor the operation of the snap valves which directly control said piston. M

The pipe line 2I8 extends to the inlet port 220 .ofthe reverse valve 201. The line 2I9 is connected through the branch lines 22I, 222, 223 and 224, to the inlet ports I31 of each of the gear-shifting cylinders 30, 3|, 32, and 33, and to the inlet port I511. of the gear-clearing or neutral cylindernj34. Another branch line 225 supplies compressed airdirectly from the main shut-off valve 206 to the neutra inlet opening 226 in the cover plate I18 of the selector I10.

The valve element 2I-I of the reverse valve 201 is provided with a forward passageway 221 and a reverse passageway 228, through which the air may bervalved to either one of two different inlet openings 229 and 230 in the cover plate I18 of the selector I10. The inlet port 2200f the valve housing 209 is provided with an elongated chamber 23I, which is of sufficient length to communicate with the port 221 when the latter is in registration with the forward port 232, and also to communicate with the port 228 when the latter is in registration with the rever port 233. The parts 232 and 233 are in turn connected to the corresponding inlets 229v and 230 of the selector I10 by means of any suitable conduits 234 and 235, respectively.

The .reverse valve housing 209 is provided with a vent port 236, intermediate the forward and reverse ports 232 and 233, and the valve element 2 is provided with a by-pass 231,

5 which interconnects the port 232 in one position of the valve, and the port 233 in the other position of the valve, with the vent port 236;- so that the port which is disconnected from the compressed air line 2I8, is connected to the vent or relief port 236. Thus, when the automatic gear-shifting mechanism is set for forward travel, by means of the setting of the valve element 2 on the dash board, the control air lines .of the reverse cylinder are inoperative and also open to atmospheric pressure if connected to the line 235, by means of the valve elements I12, I13, I14, I15 and I16. Similarly, when the gear-shifting mechanism is set for reverse travel by the corresponding setting of the valve element 2 on the dash board or control panel, the direct control valves or snap valves of the three forward cylinders are connected or vented to the atmosphere and rendered inoperative, regardless of the setting of the valves I12, I13, I14, I15, and I16.

The shut-off valve 206, adapted to render inoperative the entire gear-shifting mechanism, is also provided with a vent or relief port 238, and the by-pass 239 in the valve element thereof, whereby the lines 2 I 8 and 2I9, leading to the selector I10, both directly as well as through the reverse valve 201, as well as the branch line 22I leading to the operating cylinders, that is, the gear-shifting and gear-clearing cylinders, are all connected to the atmosphere. Thus,

when the shut-off valve or cut-offvalve 206 is set into the off or inoperative position, the

entire automatic gear-shifting mechanism is r'en dered inoperative, but the gears of the autoof the neutral cylinder 34, the 1st, 2nd,

and high cylinders 30, 32, and 33, and to the reverse cylinder 3I, respectively.

In the drawings, particularly in Figure 8, the valve element I12 is shown in the position assumed thereby when the governor of said valve element is stationary, that is, whenthe automobile and the propeller shaft or driving shaft or axle thereof is stationary.

The valve element I13, on the other hand, is shown in Fig. 8, in the position, assumed thereby with the engine at idling speed, the initial compression of the governor spring being sufficient to prevent displacement of said valve element until idling speed is exceeded. The governor spring has initial compression enough to prevent displacement of the valve at speeds below idling speed. The valve position therefore is the same for dead engine and idling condition.

The valve element I14 on the other hand, is also shown in the position assumed thereby when the engine is idling, that is, when the vacuum in the intake manifold of the engine is relatively high.

The valve elements I15 and I16 on the other hand, are shown in the neutral position of the gears. These valve .elements I15 and I16 are provided with key pins 245 and 246, respectively, which extendinto'and fit loosely within elongated slots 241 and 248, respectively, in the body of the valve housing "I, thereby to maintain said valve elements Ilia-and I16 in predetermined and fixed angular relation to the cylindrical chambers in which said valve elements are slidably mounted.

The manual control valve elements 2|0 and 2| I, shown in Figure 1, are in turn shown in their on or operative position, and in the forward position, respectively.

In Figures 8 and 9 of the drawings, it will be observed that the air passageways or channels which are formed in the upper surface I11 of the valve block or housing |1|, are connected, at certain points, to certain of the transverse cylindrical valve chambers in which the valve elements I12, I13, |14,|15, and I16 are slidably mounted. The connection of the'channels with the valve chambers is indicated by the small solid circles at the end of the channels shown in solid lines and the parallel dotted lines leading from such small circles to 'the edge of the valve chambers (the latter also being shown in dotted lines in Figure 8). The holes indicated by the small circles and parallel dotted lines, are inclined holes extending from the surface channels to the valve chamber, as indicated particularly in the sectional view in Figure 9, which is taken on lines 9-9 of Figure 8.

The connection between any pair of juxtaposed or aligned, inclined passageways 250 and 25| (see Figure 9) is obtained by registration with certain annular grooves 252 in said valve elements I 12, I13 and I14, and is obtained by registration with certain transverse rectilinear holes 253 extending through the valve elements I 15 and I16. (The valve elements I12 and I13 rotate with the rotation of the respective governors, while the valve element I14 is free to turn, although it is not definitely rotated, and the valve elements I15 and I16 are fixed against rotation by the key pins and slots 245 to 248 inclusive, as shown in Figure 8.)

The compressed air in the reservoir IN is maintained more or less constant by the compressor I60, which may be either constantly or intermittently connected to the engine, so that the operation of the engine for a suitable length of time will charge the reservoir I6| with compressed air at the suitable pressure. The pressure in the tank IBI may be maintained more or less constant, within a suitable range, either by an automatic pressure-controlled or pressure-responsive cut-out interposed between the engine of the automobile and the compressor I60, or by an automatic pressure-controlled relief valve.

connected with the reservoir IN, or by an automatic, pressure-controlled or pressure-sensitive valve mechanism or governor, associated with the compressor, which may permit the compressor to be driven by the engine, without building up pressure, whenever the pressure within the reservoir |6I is sufiiciently high.

As shown particularly in Figures 1, 8 and 9, when the cut-out valve 206 is set into the operative or on position, the compressed air is connected therethrough to the cylinder-operating.

ports of all the snap valves or direct-control valves of each of the gear-shifting cylinders 30, 3|, 32, and 33, and of the gear-clearing or neutral cylinder 34.' (See Figure 1.) Also directly through the valve 206 the air is connectedthrough 0 the line 225 to the neutral inlet opening 226 in 15 is supplied either to the inlet opening 229 or the the selector I10.

Through the manually operable valve 201, by means of which the mechanism may be set into either forward or reverse, the compressed air inlet opening 230 of the selector I 10, depending upon the position of the valve element 2| I. In Figure 1 the valve element 2| I is shown in the forward position, wherein the air is connected through the passageway 221 thereof, and through the line 234 to the forward inlet opening 229 of the selector I10. I

Forward operation of the automobile 22I is shut 011? from the respective gear-shifting pistons 42. This is the conditlon of the directcontrol valves or snap valves of the gear-shifting cylinders with the engine idling and the automobile stationary.

The direct-control valve or snap valve 8 of the gear-clearing or neutral cylinder 34, is in the open or air-admitting ition shown in Figure 2, while the engine is idling and the automobile is stationary, and this valve is set into its relief position through an impulse of controlair sent to it from the selector I10. As soon, therefore, as the pressure of the compressed air in the reservoir |6|,- acting upon the neutral piston I00, exceeds the force of the gear-clearing.

Y springs I08 and I09, the neutral piston I 00 and the slipper cam 91 are moved into their normal position shown in Figure 2, and maintained there by the force of the compressed air, until such time as the compressed air is shut off and the neutral cylinder vented by an impulse of control-air (connected to the opening I53) acting upon the end of the snap valve I I9 and displacing it into its shut-oft and vent position. When the valve is so actuated, momentarily, the slipper cam 91. is drawn to its extreme position by the pull of the springs I08 and I09, thereby "clearing all the gears, that is, shifting into neutral any gear which may be in a meshed position.

With the engine idling, and the automobile wheels stationary, and the gears in neutral, the valves are as shown in Figure 8-.

In this condition,the valves are so set, that there is no clear passageway from the inlet 229 of the selector no to either the -1st-, 2nd or high T0,

ernor I 8|, is limited to a position in which the annular groove 260 registers with the inclined ports 26| on the two sides of the valve element. At this particular enginespeed, the control air supplied passes through the inclined ports 262, on the two sides of the valve element I12 (which is then in its "dead-wheel position shown in Figure 8) and through the registering annular groove or port 203 in the valve element I12, and then through the"s tationary ports 264 on either side of the valve element I15, and through the registering movable port or passageway 265 extending] to the forward or ahead inlet opening 229, I

'thus valved to the direct control valve of the 1st cylinder by the selector I18, as a result of the acceleration of the engine, causes the-outward displacement of the direct-control valve of the "1st cylinder until the trigger and spring mechanism thereof places it into its extreme outward position where the movable port I44 thereof interconnects the stationary ports I31 and 58, and thus admits compressed air from the direct lines 22I to the gear-shifting piston 42 of the 1st cylinder. This actuates the piston and causes a displacement of the arm carried by the 1st and reverse shaft, thereby causing the operation of the corresponding rack slide and the corresponding secondary or gear shifting slide, and simultaneously (though slightly in advance of the actual meshing of the gears) causing the closing of the gas throttle to the idling position, and the disengagement of the clutch of the engine (through the action of the plunger 89, the clutch actuating connection 8|, and the throttle connection 259).

The shifting of the 1st gear into the meshing position, at once cuts off the control air to the direct-control valve or snap valve of the 1st cylinder, by reason of the shifting of the valve element I16 in the direction of the arrow I98. As the valve element I18 is moved into its extreme position in the direction of the arrow I98, the inclined movable port 269 in said valve element I16 connects the outlet 24I with a vent opening 216 in the valve housing cover plate I18, thereby relieving the control-air from the snap valve or dlrect-control valve of the 1st cylinder. As the gear shifting piston 42 of the 1st cylinder 38 reaches the limit of its travel under the influence of the direct supply of compressed air, it engages the pin or other suitable "connection I4I carried by its snap valve and causes said 'snap valve to be tripped into its inner or shut-ofi position shown in Figure 4 of the drawings. In this position, the direct supply "of compressed air is shut OE, and the vent or relief openings I58 and I46 are opened, thereby permitting the return movement of the gear shifting piston 42 under the influence of the spring 41, and also under the influence of the spring 19 and the spring of the clutch of the automobile acting through the cam shown in Figure 6. This permits a re-engagement of the clutch of the automobile and a re-opening of the gas throttle of the engine under the influence of the foot action or manual action of the operator (pressing on the foot gas pedal or acting upon a manual gas control). As stated hereinabove, the relief openings of the 1st and reverse cylinders are arranged as shown on the left side of Figure 4, thereby to moderate the re-engagement of the clutch in the two dead-wheel conditions of the automobile. Also as stated hereinabove, the size of the final relief opening I48 of the 1st and reverse cylinders, may be varied according to the clutch action desired in these two gear positions, and may also be further controlled according to the inclination of the automobile, that is, according to the grade of the road-bed or surface upon which the automobile may be resting at the time, by superimposing a pendulum-controlled valve upon the final relief of the direct operating air which otherwise vents through the opening I48. This pendulum-controlled valve may be so arranged that the opening and closing of the valve or the particular setting of the finalrelief valve is governed by the position assumed by the pendulum, and this, in turn, is controlled by the longitudinal position of the automobile with respect to the horizontal. By this means, the clutch,

actions in 1st and in reverse may be further moderated or softened if the automobile is so located that it must be started from dead-wheel" condition against an up-grade, and so that, on the other hand, the clutch action in these two positions will be quickened if the automobile is started on a down-grade.

As the automobile accelerates in 1st under the influence of the foot-action or manual action of the operator, (pressing his foot on the gas pedal or acting upon a manual gas-control) the valve element I12 responsive to the drive shaft or wheels of the automobile, moves in the direction of the arrow I98 (Figure 8) until the annular groove 21I of the valve element I12 registers with the stationary ports 212 and until the annular groove 263 registers with the stationary ports 213 ;-the registration of the former annular groove (21I) being preferably slightly in advance of the registration of the latter annular groove. (283).

This registration of the annular groove 2" with the stationary ports 212 and the registration of the annular groove 263 with the stationary ports 213, takes place at a wheel speed or drive shaft speed, which necessitates an engine speed in 1st which will cause the governor I8I connected to the engine, to bring the annular groove '214 of the valve element I13 into registration with the stationary ports 215. This connects control air through the 2nd? line 216 and through the stationary ports 211 and movable port 218,

to the stationary port 219, where it is stopped by the valve element I18 in the 1st position. The control air, however, is also connected straight through the line 288 and stationary ports 28I, and the registering annular groove 282 in the valve element I14 (the valve element I14 being sufficiently displaced by the high vacuum), to the neutral outlet opening 248, through thestationary ports 283 and the movable port 284 registering therewith in the 1st position of the valve element I16;-thereby causing the operation of the direct control valve or snap valve of the neutral cylinder, and releasing the direct air pressure from the neutral piston and permitting the slipper cam 91 to clear the gears, that is, to shift the 1st gear into its neutra position. This, in turn, shifts the valve element I18 into its neutral position, thereby breaking the neutral control line through the. channel 280 and extending the control air through the movable port 285 to the 2nd outlet 242 of the selector I18. This causes the operation of the snap valve of the 2nd cylinder, and causes said cylinder to shift the 2nd gear in the direction of the arrow I98, and also to shift the valve element I15 in the direction of the arrow I91. This, in turn, disconnects the control air and vents the snap valve of the 2nd cylinder through the inclined port 288 and the channel 281 and the stationary port 288, through the vent opening 289 in the cover plate I18 of the selector I18. The automobile then continues to accelerate in 2nd" until a predetermined wheel speed is attained,

when the annular'groove 290 registers with the stationary ports 29I, through which a controlair connection is established through the "3rd line 292 and the annular channel 293 and station- 5 ary ports 294, and through thestationary ports 295 and the movable port 298 in registration therewith, and through the stationary ports 291 and the movable port 298, to the 3rd outlet 243 of the selector I10. By this means, an impulse of control-air is supplied to the snap-valve of the 3rd cylinder, thereby causing said cylinder to shift the 2nd and high" slides out of the 2nd position, through neutral and into the high position, and causing the valve element I15 to be shifted in the direction of the arrow I98.

This disconnects the control air, and automatically vents the snap-valve of the high cylinder through the cut-out or recess 299 in the valve element I15.

The automobile may then continue to accelerate in high without any change in gears until the load on the engine is increased and the speed of the car decreased, as for instance, by too steep an up-grade, when the valve element I14 is moved in the direction I91, due to the loss of vacuum, and an impulse of control air is sent through the groove or line 300, and the stationary ports 3M and the movable or annular groove 392, and the stationary ports 288 and movable port 296, thereby causing an impulse of control-air to be sent to the snap-valve of the "2nd cylinder, thereby shifting the gears first into neutral" and then into 2nd. A further reduction in the speed of the automobile and a further load on the engine and the consequent loss of vacuum will, in turn, send an impulse of control-air through the line 303 and the stationary ports 304 and the movable port or annular channel 282, the stationary ports 305 and movable port 268, to the neutral outlet 240, thereby to permit the operation of the neutral. cylinder. Immediately thereafter, an impulse of control air is again sent through the 1st outlet 2 in the same manner as in starting from a dead stop. By this means, the gears may be shifted down not only from high" to 2nd but also from 2nd to 1st if the car speed decreases and engine load increases still further. The valve element I12 is so limited in its movement and is so adjusted with respect '50 to the automobile speed, that at a certain threshold value of automobile speed, no shiftingdown will take place, either from high to 2nd", or from 2nd to "lst, but only below these threshold speeds can the shifting-down take place.

To operate the automobile in "reverse", the valve element 2| I is moved into its outer position by pulling the handle 2I8 on'the dashboard or 60 control panel of the automobile, to its outer position. By this means, all the forward" control lines are vented through the port286 and the control air through the line 2I8 is sent through the movable port 228 and the line 285 65 into the reverse inlet 280 of the selector I19. The reverse operation will take place when the automobile is stationary orthe wheels are dead, when the movable annular groove or port 888 registers with the stationary ports 889, and the 70 movable annular g-roove or port Ill registers with the stationary ports 3, by reason of the acceleration of the engine for starting the car in reverse. The gear-shift-operated valve elements I15 and I16=being in their respective 75 neutral positions, the movable port 8| 2 is in registration with the stationary ports 3I8, and the movable port 3I4 is in registration with the stationary ports 3I5. This establishes a control air connection to the reverse outlet 244 of the selector I10 and sends an impulse of control air 5 to the snap valve or direct control valve of the reverse" cylinder, thereby causing the piston thereof to operate the gear shift into reverse, and to displace the valve element I16 in the direction of the arrow I91. The automobile is thus ll) caused to travel in the reverse direction under the control of the operator through the gas pedal. Through the recess 3I5 in the valve element I16, the snap valve of the reverse cylinder is vented. The gears will remain in 15- reverse until the engine speed is reduced when the movable annular port 3H1 registers with the stationary ports 3H and the movable port 3 registers with the stationary ports 3I6, and sends an impulse of control air from the "neutral" inlet 20 226 to the neutral" outlet 240 of the selector I10, thereby causing the operation of the neutral slipper cam 91, and thereby disengaging the gears.

Similarly, if the engine is slowed down by the 25 slowing down of the automobile, while either the 1st, 2nd or"high, or reverse gears are engaged; until port 3! registers with stationary ports 3", such registration will open a passage to the neutral outlet 244 through one 30 of the sets of movable and stationary ports provided. By this means the neutral is operated and the stalling of the engine is thus made impossible under any condition of driving.

Whenever'the gears have been shifted into 35 neutral the neutral snap valve line will be vented through the ports in valves I16 and I15 and the vent hole in the cover I18, as shown clearly in Figure 8, and also in the left portion of Figure 9. This venting of the neutral snap 40 valve line allows said snap valve to be returned to the operative position shown in Figure 2.

The vacuum-controlled valve I14 also provides a regulatory action, in that it prevents shifts from high" into 2nd gear and from 2nd 45 into 1st gear, except when the manifold vacuum is low; that is, when the engine is heavily loaded. Thus, when slowing down the car in high or 2nd gear, as for stopping, there is no shifting whatever until the engine has been slowed down sufiiciently to bring the neutral shift cylinder into action;this being the only shift, because the engine is not sumciently loaded and the intake manifold vacuum has therefore not dropped sufficiently to permit a shifting down from high to 2nd or from 2nd to 1st.

If, after having slowed down however, instead of stopping the driver opens the throttle wide, the gear, will immediately shift down, owing to the change in manifol vacuum, thus providing for the rapid acceleration desired. If on the other hand the throttle is opened only slightly, 'so as not to drop the manifold vacuum to the operative point, no shift will take place and the car will accelerate more slowly with the original gear setting.

A still further degree of fiexibility'is obtained by so proportioning the ports and travel of the valve I12, that port 2" over-travels stationary ports 212 just before port 299 registers with ports 29I. Thus, if a start is made, downhill for example, with the car moving before the throttle is opened, the gear may be shifted initially into 2nd or high instead of into 1st", depending 7 on which set of ports is in registration, and depending on how fast the automobile is moving when the throttle is opened.

Thus, it is possible also to skip a gear position 6 in accelerating the car, or to retain the low or 1st gear setting, at relatively high car speeds, by maintaining the throttle suficiently open to keep the manifold vacuum low. Valve element I14 then cuts off connection from all the snap valves until the throttle is again partially'closed.

If, when accelerating in 1st under these condltions, the speed of the automobile is increased.

until ports 290 and 2! register, instead of ports 21! and 212, the shift, when accomplished by a partial closing of the throttle, will be from "1st into high, instead of from 1st into 2nd- It will thus be seen that the .entire control of the transmission,.including a very valuable measure of voluntary control in addition to the fully automatic control, is achieved by the manipulation of the throttle only.

I am aware that my invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiments to be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention. 1

Having thus described my invention, what I hereby claim as new and desire to secure by Letters Patent, is:

1. In combination with an automobile having a prime mover and a speed change device operatively interposed between said prime mover and the driving wheels of said automobile and having a neutral position, including several sets of gears, some capable of being moved into and out of meshing relation with others, of a set of pneumatically operated gear setting devices corresponding to said movable gears, a source of pneumatic power for operating said gear-setting devices, and valved control means superimposed upon said source of power including means responsive to the speed of the automobile and the condition of loading of the prime mover for shifting from one set of gears to another, and means responsive to the engine speed for shifting the gears to neutral. I 2. In combination with an automobile having a prime mover, driving wheels, and means intermediate said prime mover and said driving wheels and operatively related to both, capable of varying the mechanical ratiobetween the prime mover and the driving wheels, of pneumatically actuated means for effecting changes in said mechanical ratio;said pneumatically actuated means being responsive to the speed of the automobile and to the speed of the prime mover.

3. In combination with an automobile having a prime mover, driving wheels, and means operatively interposed between said prime mover and said driving wheels for varying the mechanical ratio between the two, and pneumatically operated means foreffecting a variation in said mechanical ratio, said pneumatically operated means being responsive to the speed of the automobile, the speed of the prime mover, and the torque condition of the prime mover.

4; In combination with an automobile having a prime mover, driving wheels, and means operatively interposed between the prime mover and the driving wheels capable of varying-the mechanical ratio between the two, and means, intermediate s'aid prime mover and said means capable of varying the mechanical ratio, adapted to disengage the prime mover, and pneumatic means responsive to engine loading conditions for efiecting said variation in mechanical ratio and v for causing the disconnection of said prime mover in timed relationto said variations.

5. In combination with an automobile having a prime mover and driving wheels, of a speed change device operatively interposed between said prime mover and said driving wheels, including several sets of gears of diiierent mechanical ratio, capable of being selectively rendered operative and inoperative, a set of pneumatically operated gear-setting devices corresponding to said severalsets of gears, adapted to render the same operative, a pneumatically operated gear-clearing device common to each of the several sets of gears, adapted to render the ,same inoperative, and selector valves responsive to the loading of the prime mover, for controlling said gear setting and clearing devices.

6. In combination with an automobile having a prime mover and driving whee s, of a speed change device operatively interposed between said prime mover and said driving wheels, including several sets of gears of different mechanical ratio, capable of being selectively rendered operative and inoperative, a. set of pneumatically operated gear-setting devices corresponding to said'several sets of gears, adapted to render the same operative, a pneumatically operated gear-clearing device common to each of the several sets of gears, adapted to render the same inoperative, a valve associated with each of said pneumatically operated gear-setting devices and with said pneumatically operated gear-clearing device, for controlling the actuating air-supply leading to each of said devices, and pneumatic means for selectively operating said actuating valves.

7 In combination with an automobile having a prime mover and. driving wheels adapted to ,be propelled thereby, and a speed change device operatively interposed between said prime mover and the driving wheel's/of said automobile, including several sets of ears of different mechanical ratio, capable of v being alternatively rendered operative, pneumatic means capable of rendering operative any one of said sets of gears, pneumatic means capable of rendering each of said sets of gears inoperative, a source of compressed air for said pneumatic means,a pneumatically operated actuating valve for controlling the compressed air to each of said pneumatic means, and

,a plurality of selector valves operatively interposed between the source of compressed air and said actuating valves for selectively operating said actuating valves in predetermined relation to the operating conditions of the automobile.

8. In combination with an automobile having a prime mover and driving wheels adapted to be propelled thereby, a speed change device operatively interposed between said prime mover and said driving wheels, pneumatic means for operating said speed change device, a pneumatic selector device for controlling said pneumatic speedchange-operating means; said selector device including a plurality of interrelated valves, at least one of which is operated in fixed relation to, and as a result of, the operation of the speed change device, at least one of which is operated responsive to the speed of the automobile, and at least one of which is responsive to the torque condition of the prime mover.

9. In combination with an automobile having a prime mover and driving wheels adapted to be 5 propelled thereby, a speed change device operatively interposed between said prime mover and said driving wheels, pneumatic means for operating said speed change device, a pneumatic selector device for controlling said pneumatic speed-change-operating means; said selector device including a plurality of interrelated valves, at least one of which is operated in fixed relation to, and as a result of, the operation of the speed change device, and at least one of which is operated responsive to the speed or the prime mover. 10. In combination with an automobile having a prime mover and driving wheels adapted to be propelled thereby, a speed change device operatively interposed between said prime mover and said driving wheels, pneumatic means for operating said speed change device, a pneumatic selector device for controlling said pneumatic speed-change-operating means; said selector device including a plurality of interrelated valves, at least one of which is operated in fixed relation to, and as a result of, the operation of the speed change device, and at least one of which is operatedresponsive to the loading condition of the prime mover. 11. In combination with an automobile having a prime mover, driving wheels adapted to be propelled thereby, aclutch and speed change gears operatively interposed between said prime mover andsaid driving wheels, the latter being adapted to vary the mechanical ratio between the prime mover and the driving wheels, of a gear actuating device including a plurality of pneumatic cylinders and pistons therein for rendering said gears operative in any one of several gear ratios, and for rendering the same inoperative, and means actuated by each of said pistons for disengaging the clutch during the initial portion of the operative stroke thereof.

12. In combination with an automobile having a prime mover, driving wheels adapted to be propelled thereby, a clutch and speed change gears operatively interposed between said prime mover and said driving wheels, the latter being adapted to vary the mechanical ratio between the prime mover and the driving wheels, of a gear actuating device including a plurality of pneumatic cylinders and pistons therein for rendering said gears operative in any one of several gear ratios, and for rendering the same inoperative, and selector valves responsive to the loading of the prime mover, for confi'olling said gear actuating device. v

13. In combination with an automobile having a prime mover, driving wheels adapted to be propelled thereby, a clutch and speed change gears operatively interposed between said prime mover and said driving wheels, the latter being adapted to vary the mechanical ratio between the prime mover and the driving wheels, of a 65 gear actuating device including a plurality of pneumatic cylinders and pistons therein for rendering said gears operative in any one of several gear ratios, and for rendering the same inoperative, and means actuated by each of said pistons 70 for reducing the speed of the prime mover to idling, and for disengaging the clutch.

14. In combination with an automobile having a prime mover, driving wheels adapted to be propelled thereby, and.,, speed change device operatively interposed between said prime mover and said driving wheels for varying the mechanical ratio between the two, of power-actuated means for selectively operating said speed change de- -vice, and a pneumatic selector device pneumatically connected with said power-actuating means and adapted to control the same responsive to the operating conditions of the automobile;said pneumatic selector device including a plurality of inter-related valves, some having,- and some being capable of being set into, predetermined operative positions corresponding to each of the several positions of the speed change device, and

some being set automatically responsive to the speed of the automobile and the power-loading oi the prime mover.

15. In combination with an automobile having a prime mover, driving wheels adapted to be propelled thereby, a speed change device operatively interposed between said prime mover and said driving wheels and adapted to be set into a plurality of positions to vary the mechanical ratio between the prime mover and the driving wheels, of a power-actuated speed change operating device adapted automatically to set said speed change devices into any one of its several positions, and including a pneumatic selector having a plurality of inter-related movable valve elements, some being movable in predetermined and fixed relation to the settings of said speed change device, one being moved generally responsive to the speed of the automobile, and one being moved generally responsive to the speed of the prime mover.

16. In combination with an automobile having an internal combustion engine, driving wheels adapted to be propelled thereby, a clutch and speed change gears operatively interposed between said internal combustion engine and said driving wheels, the latter being adapted to vary the mechanical ratio between the internal combustion engine and the driving wheels, 01' a gear 1'7. In combination with an automobile having an internal combustion engine, driving wheels adapted to be propelled thereby, a clutch and speed change gears operatively interposed 'between said internal combustion engine and said driving wheels, the latter being adapted to vary the mechanical ratio between the internal combustion engine and the driving wheels, of a gear actuating device including a plurality of pneumatic cylinders and pistons therein, means operatively interposed between said pistons and said speed change gears, for enabling said pistons to render said gears operative in any one of several positions of diflerent gear ratios, and to render said gears inoperative, means actuated by said pistons for causing a disengagement oi the clutch in .timed relation to the setting of the gears,

.means actuated by said pistons for causing the tion of the clutch, pneumatically actuated valves to the settings oi said speed change gears and responsive to the speed of the automobile and the load conditions of the internal combustion engine.

HAVILAND H. PLA'I'I. 5 

